Jonathan Dimbleby’s organic credentials are impeccable.

Not only has he been running beef and sheep herds on his farm near Bath but, since 1997, he has also been president of the Soil Association.

But this was not always the case.

After attending the Royal Agricultural College, he was impressed by the brave new world of cheap, intensively produced food. A career, however, in the media, not farming, beckoned and this view was never put into practice.

It was only when reporting crises across the world, especially the 1973 Ethiopian famine, that he came to the conclusion that much of the suffering was abetted by human mismanagement of the environment, like soil erosion, and it was time to treat the earth more sympathetically.

In 1992, Mr Dimbleby fulfilled his long-standing ambition by buying Upper Langridge Farm, near Bath.

Including rented land, the business grew to 120ha (300 acres) and the hands-on farming only re-enforced his view of the benefits of organic production.

“Our oldest cow has just had her 13th or 14th calf. If you nurture animals they can be extremely efficient producers.”

Since taking on his role at the Soil Association he says he has been heartened that relations between conventional and organic farmers have improved.

“Before it was open warfare, now they at least respect each other, which can mean nothing but good.”

Sadly, he says, his own farming days have to come to an end due to broadcasting commitments, but he will still be involved fully with Bath Organic Farms, the award-winning business he set up with farmer Paul Robinson that has just agreed a deal to supply Bath Rugby Club with organic burgers.

“I will still be able to make speeches and hope in some ways to give more time to articulating the cause,” adds Mr Dimbleby, best known for his firm-yet-fair chairmanship of Radio 4’s Any Questions and Any Answers as well as that infamously revealing interview with Prince Charles, perhaps the highest-profile of all organic farming’s exponents.

His persuasive powers will be needed. Although the sale of organic produce is rocketing – reportedly by 2m each month – the sector faces a number of serious challenges, not least from imported organic food, which accounts for 56% of sales.

“It is a real dilemma for me personally because I speak with two hats on – the environment and development.”

As chairman of Voluntary Service Overseas (VSO), Mr Dimbleby has just visited Malawi and he concedes that any exports that earn the country foreign exchange must be good.

But he is also concerned with the environmental damage done by flying produce across the globe.

“One thing we need to see is a tax on the real costs to the economy and the environment of global air transport.

The great strength of local and seasonal produce is that it delivers genuine traceability and is very efficient in environmental terms. Our farms are only a few miles from the shop.”

Retail power is another area for concern, with the cost of organic food falling sharply.

“I worry greatly.”

We know that conventional producers have already had their margins slashed to the bone.

I feel very sorry for your readers and regard the loss of the family farm as nothing short of catastrophic.

“There must be a fair means for farmers to produce on a value-added basis.

As it is, the power of supermarkets to bear down on producers is damaging to the food production process and to us all. We have to pay a fair price for food.”

As it is, Mr Dimbleby admits he would not have been able to sustain his farm effectively without the income from his “day job”, but says that may be a growing trend.

“Because of the continuing critical condition of British farming it is at our peril that we mock part-time farmers.”

Although he says he will be sad to say goodbye to his farming days – lambing was a particular favourite – and is hopeful that his farm will stay in organic production, he plans to carry on enjoying the rural environment.

“I have the romantic view that it all starts on the land.”

andrew.shirley@rbi.co.uk